NEW YORK — They are responsible for some big hit singles in recent years, but now twin sisters, Liv and Mim, otherwise known as NERVO, are focusing on one thing: themselves.

The Australian DJs, who are CoverGirl brand correspondents, are gearing up for a very busy summer, which includes traveling the world, a Las Vegas residency and working on their much-anticipated debut album.

"We are working on so much. We are trying to finish our album, so we are constantly in the studio," Liv told MTV News at the CoverGirl's BeautyREMIX event in New York City. "We also have a bunch of residencies around the world."

Those residencies include one in Ibiza and another at Las Vegas hot spot Hakkasan at the MGM Grand where they will no doubt be spinning their new single, "Hold On," a track made to get people on their feet and into the clubs.

If you're expecting to see what else the sisters have in store for their new music, you may have to wait a few more months because the duo is a bit indecisive when it comes to their tracks.

"Well, it's the never-ending album. We keep changing our mind," Liv said. "We feel like we have a bunch of material, and we'll write something else, and we are like, 'OK, this is where we want to take it.' So, I think there will come a time and be like, 'OK, these are the records, let's now finish them,' and hopefully we will have it done by the end of the year."

NERVO have collaborated with some of the biggest EDM and pop artists in the world, including David Guetta, Afrojack and Ke$ha, and while they are still working with some of those artists, they decided that when it came time to work on their own album, it was just going to be about them.

"On our album, we are doing a lot of it," Mim said. "But we are still working with people like David Guetta, Nicky Romero, Avicii, Afrojack we are working with all our DJ friends for their records and we are working on their projects and our projects as well."